Datasheet
Table Of Contents
- General Description
- Key Features
- Applications
- System Diagrams
- Contents
- Figures
- Tables
- Legal
- Product Family
- 1 Terms and Definitions
- 2 Block Diagram
- 3 Pinout
- 4 Characteristics
- 5 Functional Description
- 5.1 Features Description
- Driving LRA and ERM Actuators
- Automatic LRA Resonant Frequency Tracking
- Wideband LRA Support
- I2C and PWM Input Streaming
- Low Latency I2C/GPI Wake-Up from IDLE State
- Three GPI Sequence Triggers for up to Six Independent Haptic Responses
- On-Board Waveform Memory with Amplitude, Time, and Frequency Control
- Active Acceleration and Rapid Stop for High-Fidelity Haptic Feedback
- Continuous Actuator Diagnostics and Fault Handling
- No Software Requirements with Embedded Operation
- Differential Output Drive
- Current Driven System
- Configurable EMI Suppression
- Automatic Short Circuit Protection
- Ultra-Low Power Consumption with State Retention
- Ultra-Low Latency in STANDBY State
- Supply Monitoring, Reporting, and Automatic Output Limiting
- Open- and Closed-Loop Modes
- Open-Loop Sine/Custom Wave Drive Support
- Small Solution Footprint
- Additional Features
- 5.2 Functional Modes
- 5.3 Resonant Frequency Tracking
- 5.4 Active Acceleration and Rapid Stop
- 5.5 Wideband Frequency Control
- 5.6 Device Configuration and Playback
- 5.7 Advanced Operation
- 5.7.1 Frequency Tracking
- 5.7.2 Rapid Stop
- 5.7.3 Initial Impedance Update
- 5.7.4 Amplitude PID
- 5.7.5 Wideband Operation
- 5.7.6 Custom Waveform Operation
- 5.7.7 Embedded Operation
- 5.7.8 Polarity Change Reporting for Half-Period Control in DRO Mode
- 5.7.9 Loop Filter Configuration
- 5.7.10 UVLO Threshold
- 5.7.11 Edge Rate Control
- 5.7.12 Double Output Current Range
- 5.7.13 Supply Monitoring, Reporting, and Automatic Output Limiting
- 5.7.14 BEMF Fault Limit
- 5.7.15 Increasing Impedance Detection Accuracy
- 5.7.16 Frequency Pause during Rapid Stop
- 5.7.17 Frequency Pause during Rapid Stop
- 5.7.18 Coin ERM Operation
- 5.8 Waveform Memory
- 5.9 General Data Format
- 5.10 I2C Control Interface
- 5.1 Features Description
- 6 Register Overview
- 7 Package Information
- 8 Ordering Information
- 9 Application Information
- 10 Layout Guidelines
DA7280
LRA/ERM Haptic Driver with Multiple Input Triggers,
Integrated Waveform Memory and Wideband Support
Datasheet
Revision 3.0
30-Jul-2019
CFR0011-120-00
41 of 76
© 2019 Dialog Semiconductor
5.7.17 Frequency Pause during Rapid Stop
If DA7280 is used with LRAs that have significant BEMF voltage amplitude that can transiently
exceed the IR drop across an actuator when reversing the phase of the drive signal, it is
recommended to set DELAY_BYPASS to 0.
5.7.18 Coin ERM Operation
The term coin ERM is used to describe an eccentric rotating mass actuator that is flat and has coin-
like external appearance. The eccentric rotating mass is circular and contains two coil windings that
are used for commutation, see Figure 23.
INN
INP
Plan View Elevation View
2
1
Case Case
Rotor Top
Rotor
Rotor Bottom
Stator
Coils
Commutator PCB
Stator
Magnet
Brushes
Shaft
Electrical Commutation
1 2
A
A’
B
B’
C
C’
Commutator PCB Electrical Diagram
A
A’
B
B’
C
C’
1 2
A
A’
B
B’
C
C’
Commutation Event 1: Single Inductor
1 2
A
A’
B
B’
C
C’
Commutation Event 2: Double Inductor
VOUT Constant Current
Driven System
Time [s]
Voltage [V]
VOUT
Coil 1 in series with Coil 2
Coil 1 or Coil 2
View w/o Case
Rotor
Stator
Coil 1 and 2
in parallel
1 2
A
A’
B
B’
C
C’
Commutation Event 3: Parallel Inductors
Figure 23: Coin ERM Physical and Electrical Summary
Due to the commutation of the motor, the impedance varies between one coil, two coils in series, and
for very short periods two coils in parallel. Due to this behavior, DA7280 cannot extract the BEMF
and actuator motion is not detectable for coin ERM actuators. Therefore, Active Acceleration and
Rapid Stop features are not available. Manual overdrive or underdrive of the coin ERM to speed up
the transition between two levels of acceleration is possible and recommended for better user
experience. Note that due to the varying impedance and the constant current drive of DA7280, the
output voltage will vary, with no effect on the performance of the DA7280, see Figure 23.
Recommended setup specific for a coin ERM, in addition to generic ERM setup described in
Section 5.6.2:
● ACCELERATION_EN = 0
● RAPID_STOP_EN = 0
● AMP_PID_EN = 0
● V2I_FACTOR_FREEZE = 1
● CALIB_IMPEDANCE_DIS = 1
● BEMF_FAULT_LIM = 0
● Set the V2I factor using the single winding impedance, see Section 5.6.2
● Set IMAX using the maximum start-up current, see Section 5.6.2